Servosystem with varying angular relationships between a primary control axis and one or more secondary controlled axes

ABSTRACT

A reference transducer is connected to a control shaft via a transmission. Turning the control shaft through one angle turns the reference transducer through a second unique angle. Conventional servosystem apparatus interconnects the reference transducer with the responsive transducers which are directly connected to response shafts. Consequently, the response shafts are turned through the second angle, and not through the same first angle as the control shaft.

United States Patent lnventors Wilmer Graziano Via Bertarino, 8,Tortona; Guido Ruggeri, Via Broggi, 7, Milan, Italy Appl. No. 615,951Filed Feb. 14, 1967 Patented Apr. 27, 1971 Priority Feb. 15, 1966SERVOSYSTEM wmi VARYING ANGULAR RELATIONSHIPS BETWEEN A PRIMARY CONTROLAXIS AND ONE OR MORE SECONDARY CONTROLLED AXES 1 Claim, 2 Drawing Figs.

US. Cl 318/573, 318/654, 318/660 int. Cl G05b 19/24 Field of Search..318/20270,

[56] References Cited UNITED STATES PATENTS 3,328,655 6/1967 Tripp 3 l8/20.130X

3,141,121 7/1964 Moody etal.... ....3l8/(20.270UX) 3,178,663 4/1965 Kahn....318/(20.270UX) 3,217,318 11/1965 Masel..... ....318/(20.270UX)3,353,095 11/1967 Farrand.. ....318/(20.735UX) 3,373,326 3/1968 Fan-and....318/(20.270UX) 3,396,321 8/1968 Pellecchia ..318/(20.730UX) PrimaryExaminer-T. E. Lynch Attorney-Littlepage, Quaintance, Wray and AisenbergABSTRACT: A reference transducer is connected to a control shaft via atransmission. Turning the control shaft through one angle turns thereference transducer through a second unique angle. Conventionalservosystem apparatus interconnects the reference transducer with theresponsive transducers which are directly connected to response shafts.Consequently, the response shafts are turned through the second angle,and not through the same first angle as the control shaft.

Patentd 2 7, 1 971 [IIIIIIIII 111111111111 1 1 1 5lllllrlIl/Illlllllllllll INVENTORS ATTORNEYS WI/mer This inventionrelates to a servosystem comprising a plurality of electromagneticangular position transducers for achieving varying ratios between aprimary axis and one or more secondary axes.

The device according to the invention is particularly I adapted for useon machine tools. a

More particularly, the above servosystem is characterized by comprisinga plurality of electromagnetic angular position transducers, one ofwhich is connected during rotation to the primary axis and operates as areference transducer, while the other or others are respectively rigidlyconnected to one or more secondary axes and operate as transducersdetecting the movements thereof, as well as one or more continuous ordiscontinuous speed variators, inserted between one or more individualaxes and respective transducers, said servosystem being particularlyadapted for use on machine tools.

The accompanying drawing shows by way of nonrestrictive example adiagram for the servosystem according to the present'invention, andparticularly:

FIG. 1 is partly a sectional and party a general view of the controlmembers for a machine tool, on which one of the electromagnetictransducers forming part of the device is inserted and connected to theprimary axis by a speed variator.

FIG. 2 is partly a sectional and partly a perspective view of a portionof a machine tool on which two electromagnetic I transducers formingpart of the device are mounted.

, Referring to the figures, it can be seen that the servosystemaccording to the present invention comprises aplurality ofelectromagnetic angular position transducers of the synchroorresolver-type. One of these, designated at l of FIG. 1, rotatesintegrally with an axis 3, the motion of which is controlled by means ofa continuous or discontinuous angular speed variator 8 schematicallyshown in FIG. 1 on the axis 4 of the machine on which the device isapplied.

The other electromagnetic transducers, designated at 2 in FIG. 2, areeach integral with a secondary axis of the machine, the rotation ofwhich linearly depends on the rotary or translatory motions to beadjusted; in the figure such axes are formed of the screws 5 and 5 Therotation of screw 5 in either direction causes the displacement ofcarriage 6 in the direction of one of the arrows c, d. The rotation ofscrew 5' in either direction causes the displacement of slide 7 in thedirection of one of the arrows a, b. The two above displacementsaccording to arrows a, b and c, d can be simultaneous or subsequent toone v another.

Transducer 1 operates as a reference, while the other transducersdesignated at 2 operates as detecting transducers for the movements tobe adjusted.

The output signals of the first transducer are compared with those ofeach of the other transducers and these signals, suitably demodulatedand amplified, are respectively used for controlling the individualoperations.

Therefore, axis rotations are provided according to predetermined ratioswith the rotation of a single control axis, and thus the desired feedingfor each revolution of the latter.

In the above exemplary described embodiment, a speed variator isinterposed between the primary axis and the reference transducer, whilstthe other transducers are rigidly connected to the secondary axes orshafts.

However, it is to be understood that the present invention contemplatesother embodiments, in which a continuous or discontinuous speed variatoris inserted between the transducer and the relative secondary axis.

We claim:

l. A servosystem for varying relative angular displacement of a primarycontrol shaft and at least one secondary controlled shaft in machinetools comprising:

mounted for rotation in the base,

a control dial having outward facing indicia connected to one end of theprimary shaft for rotation therewith,

a 'variable speed variator having an input and output selectivelyinterconnected by means for varying the relationship between the inputand output, the input of the speed variator being connected to thesecond end of the primary shaft opposite the dial,

a primary magnetic angular position transducer having a rotor connectedto the output of the speed variator,

a secondary shaft rotatably mounted on the base,

a motor having a rotor connected to the secondary shaft for turning thesecondary shaft,

a secondary electromagnetic angular position transducer having a rotorconnected to the secondary shaft for turning therewith,

a comparator connected to the primary and secondary transducers forproducing an error signal, and

a motor control including an amplifier connected to the comparator andto the motor for turning the secondary shaft until no error signal isproduced.

1. A servosystem for varying relative angular displacement of a primarycontrol shaft and at least one secondary controlled shaft in machinetools comprising: a base mounted on a machine, a primary control shafthaving first and second ends mounted for rotation in the base, a controldial having outward facing indicia connected to one end of the primaryshaft for rotation therewith, a variable speed variator having an inputand output selectively interconnected by means for varying therelationship between the input and output, the input of the speedvariator being connected to the second end of the primary shaft oppositethe dial, a primary magnetic angular position transducer having a rotorconnected to the output of the speed variator, a secondary shaftrotatably mounted on the base, a motor having a rotor connected to thesecondary shaft for turning the secondary shaft, a secondaryelectromagnetic angular position transducer having a rotor connected tothe secondary shaft for turning therewith, a comparator connected to theprimary and secondary transducers for producing an error signal, and amotor control including an amplifier connected to the comparator and tothe motor for turning the secondary shaft until no error signal isproduced.